The purpose of this research is to conduct "enhanced surveillance and operations research using population- based data" from the Kentucky Cancer Registry (KCR). KCR has been a part of the Centers for Disease Control and Prevention (CDC), National Program of Cancer Registries (NPCR) since the inception of the initiative and KCR is one of the recent additions to the Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute. Byfocusing on improved "completeness, timeliness, quality, and use of first course of treatment and stage data" we will strengthen the capacity of an already outstanding cancer registry to describe patterns of care for breast and prostate cancer. We will focus on understanding how tumor, patient, provider, and health system characteristics affect the degree to which patients receive the recognized standard of care. To this end we propose the following aims: (1) Describe treatment patterns for stages I through III of female breast cancer in terms of the proportion who receive the recognized standard of care; (2) Describe treatment patterns for all stages of prostate cancer; (3) Determine how tumor, patient, provider, and health system characteristics affect treatment strategies for breast and prostate cancer; (4) Assess the completeness and quality of stage and first course of treatment data, and compare the latter to evidence of treatment from Medicare claims data. We believe that the proposed study will make a significant contribution toward building the capacity to conduct enhanced surveillance at an already outstanding cancer registry in the state of Kentucky. We also believe that this study will help us to understand the degree to which breast and prostate cancer patients receive the recognized standard of care, and the factors that move doctors and patients to deviate from that standard. Such understanding should help us distinguish those factors that represent legitimate and reasonable causes for such deviation from the factors that may represent unreasonable causes, such as barriers to access or discrimination.